Light source device and projector

ABSTRACT

[Solution] Provided is a light source device including: at least one light source unit (110) that emits substantially parallel light in a predetermined wavelength band; and a light guide unit (120, 130) that guides the light from the light source unit (110) toward a light collection spot (143). The light from the light source unit (110) is sequentially reflected by a concave mirror (121) and a convex mirror (122) and is guided toward the light collection spot (143) in the light guide unit (120, 130).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 15/520,071, filed Apr. 18, 2017, which is aNational Stage of PCT/JP2015/077817 filed on Sep. 30, 2015, and claimsthe benefit of priority from prior Japanese Patent Application No. JP2014-219313 filed in the Japan Patent Office on Oct. 28, 2014. Each ofthe above-referenced applications is hereby incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a light source device and a projector.

BACKGROUND ART

In recent years, projectors using solid-state light sources such aslight emitting diodes (LEDs) or laser diodes (LDs) as light sources havebecome widespread. Some light sources for the projectors use thesolid-state light sources such as LDs as direct light sources whileothers use light from the solid-state light sources as excitation lightand use fluorescent substances emitting fluorescent light due toirradiation with the excitation light as light sources.

Thus, various technologies for efficiently irradiating the fluorescentsubstances with the light from solid-state light sources have beendeveloped. For example, Patent Literature 1 discloses a light sourcedevice that reflects light from a solid-state light source by a concavemirror and collects the light on a fluorescent substance.

CITATION LIST Patent Literature

Patent Literature 1: JP 2014-82144A

DISCLOSURE OF INVENTION Technical Problem

Here, an operation of adjusting a position and a size of a lightcollection spot on a fluorescent substance may occur in assembling alight source device, for example. In the adjusting operation,arrangement positions of a solid-state light source and other opticalmembers, for example, are finely adjusted.

Although the light collection spot can be adjusted by changing thearrangement positions of the optical members also in the technologydescribed in Patent Literature 1, it is difficult to state that theadjustment of the light collection spot can be easily performed sinceboth the position and the size of the light collection spot change inconjunction with the change of the positions of the optical members dueto the configuration of the technology. It is also difficult torespectively adjust the position and the size of the light collectionspot with high precision. There is a concern that the quality of lightoutput from the light source device may be degraded unless the positionand the size of the light collection spot can be controlled with highprecision.

Thus, the present disclosure proposes a novel improved light sourcedevice and a projector capable of obtaining output light with higherquality.

Solution to Problem

According to the present disclosure, there is provided a light sourcedevice including: at least one light source unit that emitssubstantially parallel light in a predetermined wavelength band; and alight guide unit that guides the light from the light source unit towarda light collection spot, in which the light from the light source unitis sequentially reflected by a concave mirror and a convex mirror and isguided toward the light collection unit in the light guide unit.

According to the present disclosure, there is provided a projectorincluding: a light source device including at least one light sourcethat emits substantially parallel light in a predetermined wavelengthband and a light guide unit that guides the light from the light sourceunit toward a light collection unit; and an image projection device thatgenerates an image by using the light output from the light sourcedevice and projects the image, in which the light from the light sourceunit is sequentially reflected by a concave mirror and a convex mirrorand is guided toward the light collection spot in the light guide unitof the light source device.

According to the present disclosure, the light from the light sourceunit is sequentially reflected by the concave mirror and the convexmirror and is guided toward the light collection spot. With such aconfiguration, it is possible to respectively independently adjust therespective positions in two mutually different directions in a planeperpendicular to the light reflected by the convex mirror and the sizeof the light collection spot by adjusting positions of the convex mirrorin three axis directions. Therefore, it is possible to more easily andmore precisely adjust the position and the size of the light collectionspot. Accordingly, it is possible to further improve a quality of thelight output from the light source device, which can depend on theposition and the size of the light collection spot, by appropriatelyadjusting the position and the size of the light collection spot.

Advantageous Effects of Invention

According to the present disclosure, it is possible to obtain outputlight with higher quality as described above. Note that the effectsdescribed above are not necessarily limitative. With or in the place ofthe above effects, there may be achieved any one of the effectsdescribed in this specification or other effects that may be graspedfrom this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration example of a lightsource device according to a first embodiment.

FIG. 2 is a diagram illustrating a configuration example of a typicallight source device.

FIGS. 3A and 3B are explanatory diagrams for explaining a change in anangle of a planar mirror of the typical light source device.

FIGS. 4A, 4B and 4C are diagrams illustrating a change in a lightcollection spot when an angle of the planar mirror with respect to a Zaxis direction is changed in the typical light source device.

FIGS. 5A, 5B and 5C are diagrams illustrating a change in the lightcollection spot when a convex mirror is moved in an X axis direction anda Y axis direction in the light source device according to the firstembodiment.

FIGS. 6A, 6B, 6C and 6D are diagrams illustrating a change in the lightcollection spot when the convex mirror is moved in the Z axis directionin the light source device according to the first embodiment.

FIG. 7 is a diagram illustrating a configuration example of a lightsource device according to a second embodiment.

FIG. 8 is a diagram illustrating a configuration example of a lightsource device according to a third embodiment.

FIG. 9 is a diagram illustrating a formation example of a lightcollection spot in the light source device according to the thirdembodiment.

FIG. 10 is a diagram illustrating a configuration example of a lightsource device according to a fourth embodiment.

FIG. 11 is a diagram illustrating another configuration example of thelight source device according to the fourth embodiment.

FIG. 12 is a diagram illustrating a configuration example of a lightsource device according to a fifth embodiment.

FIG. 13 is a graph illustrating a spectrum of fluorescent light in aYAG-based fluorescent substance.

FIG. 14 is a diagram illustrating a configuration example of a lightsource device according to a sixth embodiment.

FIG. 15 is a diagram illustrating a configuration of a projectoraccording to a first configuration example.

FIG. 16 is a diagram illustrating a configuration of a projectoraccording to a second configuration example.

FIG. 17 is a diagram illustrating a configuration of a projectoraccording to a modification example of the second configuration example.

FIG. 18 is a diagram illustrating a configuration of a projectoraccording to a third configuration example.

FIG. 19 is a diagram illustrating a configuration of a projectoraccording to a fourth configuration example.

MODES FOR CARRYING OUT THE INVENTION

Hereinafter, (a) preferred embodiment(s) of the present disclosure willbe described in detail with reference to the appended drawings. In thisspecification and the appended drawings, structural elements that havesubstantially the same function and structure are denoted with the samereference numerals, and repeated explanation of these structuralelements is omitted.

Now, description will be given in the following order.

1. First Embodiment

1-1. Configuration of light source device1-2. Comparison with typical light source device1-2-1. Comparison of device configurations1-2-2. Comparison of methods for adjusting light collection spot

2. Second Embodiment 3. Third Embodiment 4. Fourth Embodiment 5. FifthEmbodiment 6. Sixth Embodiment

7. Application examples7-1. First configuration example7-2. Second configuration example7-3. Third configuration example7-4. Fourth configuration example7-5. Summary of application examples8. Supplementary notes

1. First Embodiment 1-1. Configuration of Light Source Device

With reference to FIG. 1, a configuration of a light source deviceaccording to a first embodiment of the present disclosure will bedescribed. FIG. 1 is a diagram illustrating a configuration example ofthe light source device according to the first embodiment.

Referring to FIG. 1, a light source device 10 according to the firstembodiment mainly includes a light source unit 110, a light guide unit120, a light collection unit 130, a fluorescent substance wheel 140, anda spectroscopy unit 150. The light source device 10 according to thefirst embodiment is a light source device that outputs at leastfluorescent light emitted from a fluorescent substance by irradiatingthe fluorescent substance of the fluorescent substance wheel 140 withlight from the light source unit 110.

The light source unit 110 emits substantially parallel light in apredetermined wavelength band. The light source unit 110 includes atleast one LD that is a solid-state light source and at least onecollimator lens that substantially parallelizes the light emitted fromthe LD. In the first embodiment, the light source unit 110 is configuredsuch that a plurality of combinations, each of which includes the LD andthe collimator lens, for example, are aligned in a predetermineddirection. In FIG. 1, light from the plurality of LDs is represented bya single representative solid line.

In the first embodiment, LDs that emit laser light in a blue band (awavelength band from about 400 (nm) to 500 (nm)) are used as the lightsource unit 110. However, the first embodiment is not limited to such anexample. As will be described later, the light from the light sourceunit 110 is used as excitation light for causing the fluorescentsubstance of the fluorescent substance wheel 140 to emit light.Therefore, performances of the LDs that form the light source unit 110may be appropriately selected in accordance with desired properties ofthe fluorescent light, that is, in accordance with properties of thefluorescent substance used.

In the following description, a direction in which the light source unit110 emits light will be defined as a Z axis direction. Also, twodirections that perpendicularly intersect each other in a planeperpendicular to the Z axis direction will be defined as an X axisdirection and a Y axis direction. In the example illustrated in FIG. 1,the LDs that form the light source unit 110 are aligned in one arrays ora plurality of arrays in the Y axis direction.

The light guide unit 120 guides the light from the light source unit 110toward the fluorescent substance wheel 140. The light guide unit 120includes a concave mirror 121 and a convex mirror 122. As shown in thedrawing, the light from the light source unit 110 is reflected by theconcave mirror 121 and the convex mirror 122 in this order and is thenguided toward the fluorescent substance wheel 140.

The concave mirror 121 is a plate-like member with a substantiallyrectangular shape and is arranged such that a reflecting surface thereoffaces the light source unit 110. The concave mirror 121 is formed suchthat the reflective surface thereof has a paraboloidal surface andreflects the light from the light source unit 110 toward the convexmirror 122. Since the reflective surface of the concave mirror 121 isthe paraboloidal surface, the light from the plurality of LDs in thelight source unit 110 can be more effectively collected at the convexmirror 122. Use of the concave mirror 121 can realize a function ofcollecting light at a predetermined position (on the reflective surfaceof the convex mirror 122 in the first embodiment) with a smallerconfiguration than that in a case where other optical members such as alens group or a planar mirror are used.

However, the shape of the concave mirror 121 is not limited to such anexample. The shape and the properties of the concave mirror 121 canappropriately be set in consideration of arrangement positions of theLDs that form the light source unit 110, the size and the incident angleof a light flux that is incident on the concave mirror 121, and theposition and the size of the light collection spot 143 on thefluorescent substance wheel 140, which will be described later, forexample.

For example, the reflective surface of the concave mirror 121 may be aspherical surface or another free curved surface. Also, the shape of theconcave mirror 121 is not limited to a substantially rectangular shape,and the concave mirror 121 may be formed into a bowl shape, for example,so as to cover the light source unit 110. However, forming the concavemirror 121 into a substantially rectangular shape as illustrated in thedrawing makes it possible to further downsize the configuration of theconcave mirror 121 and to downsize the entire light source device 10 aswell.

The convex mirror 122 has a substantially semi-spherical shape and isarranged at a position corresponding to the light collection point bythe concave mirror 121 such that the reflective surface thereof faces ina positive direction of the Z axis direction. The convex mirror 122 is aspherical mirror in which the reflective surface is a spherical surface.The light from the light source unit 110, which has been reflected bythe concave mirror 121 and has been incident on the convex mirror 122,is further reflected by the convex mirror 122 and is guided toward thefluorescent substance wheel 140 arranged in the positive direction ofthe Z axis. In FIG. 1, the light after being reflected by the convexmirror 122 of the light guide unit 120 is represented by a singlerepresentative solid line for simplification.

The shape of the convex mirror 122 is not limited to the aforementionedexample. The shape and the properties of the convex mirror 122 canappropriately be set in consideration of a positional relationship withthe concave mirror 121, the size and the incident angle of a light fluxthat is incident on the convex mirror 122, and the position and the sizeof the light collection spot 143 on the fluorescent substance wheel 140,which will be described later, for example. For example, the reflectivesurface of the convex mirror 122 may be an aspherical surface. Forexample, the convex mirror 122 may not be a substantially semi-sphericalshape.

However, at least one of the reflective surfaces of the concave mirror121 and the convex mirror 122 is preferably an aspherical surface. Byemploying an aspherical shape for at least one of the reflectivesurfaces of the concave mirror 121 and the convex mirror 122, it ispossible to reduce aberration of the light that is incident on thefluorescent substance wheel 140 and to improve efficiency in collectingthe light at the fluorescent substance wheel 140. At this time, it ispreferable that the reflective surface of the concave mirror 121 is anaspherical surface while the reflective surface of the convex mirror 122is a spherical shape. In this case, it is possible to use a commerciallyavailable spherical mirror as the convex mirror 122 and to therebyreduce manufacturing costs.

Here, the arrangement positions are adjusted such that an optical axisof the concave mirror 121 and an optical axis of the convex mirror 122(for example, a central axis of a paraboloidal surface that forms thereflective surface of the concave mirror 121 and a central axis of aspherical surface that forms the reflective surface of the convexmirror) substantially coincide with each other in the first embodiment.In this manner, the light reflected by the convex mirror 122 becomessubstantially parallel light and is then guided toward the fluorescentsubstance wheel 140.

The light source device 10 can be provided with an adjustment mechanismfor adjusting positions of the convex mirrors 122 in the three axisdirections (the X axis direction, the Y axis direction, and the Z axisdirection). The adjustment mechanism has a function of moving the convexmirror 122 in parallel to the three axis directions, respectively.

The adjustment mechanism adjusts a positional relationship between boththe central axes such that they substantially coincide with each otherif the central axes deviate from each other due to an error caused whenthe concave mirror 121 and the convex mirror 122 are assembled, forexample. Also, it is possible to adjust the position and the size of thelight collection spot 143 on the fluorescent substance wheel 140, whichwill be described later, by adjusting the positions of the convex mirror122 in the three axis directions in the light source device 10 as willbe described later. That is, the adjustment mechanism can also adjustthe light collection spot 143.

As a specific configuration of the adjustment mechanism, various knownconfigurations that can be typically used for moving members in parallelcan be used. For example, the adjustment mechanism may be formed of anactuator that is made of a drive device for a motor, for example, andmay electrically move the positions of the convex mirror 122.Alternatively, the adjustment mechanism may be formed of a combinationof transmission members such as a gear, for example, and may manuallycause mechanical movement of the positions of the convex mirror 122.

The fluorescent substance wheel 140 includes a disk-shape substrate 141and a fluorescent substance (not illustrated) provided on the substrate141. The fluorescent substance wheel 140 is arranged such that asurface, on which the fluorescent substance is provided, of thesubstrate 141 faces the light guide unit 120 (that is, so as to face thenegative direction of the Z axis). A motor 142 that drives thefluorescent substance wheel 140 is connected to the center of thesubstrate 141, and the fluorescent substance wheel 140 can rotate abouta normal line passing through the center of the substrate 141 as arotation axis.

The fluorescent substance provided at the fluorescent substance wheel140 functions as a light emitting substance that is excited with lightfrom the light source unit 110 and emits fluorescent light in a longerwavelength band than the wavelength of the light. In the firstembodiment, the fluorescent substance is a YAG(yttrium/aluminum/garnet)-based fluorescent substance, is excited withthe light in a blue band from the light source unit 110, and emits lightfrom a green band to a red band. The fluorescent substance wheel 140according to the first embodiment is a reflective-type fluorescentsubstance wheel, and the light from the fluorescent substance isradiated in the incident direction of the light from the light sourceunit 11 (that is, the negative direction of the Z axis). However, thefirst embodiment is not limited to such an example, and various knownfluorescent substances may be used as the fluorescent substance of thefluorescent substance wheel 140 so as to be able to obtain light in adesired wavelength band in accordance with a purpose of the light sourcedevice 10, for example.

The light collection unit 130 that collects the substantially parallellight which has been guided by the light guide unit 120 on thefluorescent substance of the fluorescent substance wheel 140 is providedbetween the light guide unit 120 and the fluorescent substance wheel140. The light collection unit 130 is arranged such that an optical axisthereof substantially coincides with the optical axes of the concavemirror 121 and the convex mirror 122. The light collection unit 130collects the light on the light collection spot 143 on the fluorescentsubstance, and the light collection spot 143 emits the fluorescentlight. The light guide unit 120 and the light collection unit 130 can bereferred to as an optical system that collects the light from the lightsource unit 110 at the light collection spot 143. Therefore, the lightguide unit 120 (the concave mirror 121 and the convex mirror 122) andthe light collection unit 130 will be collectively referred to as alight collection optical system in some cases in the followingdescription.

In the illustrated example, the light collection unit 130 includes aplurality of convex lenses. However, the first embodiment is not limitedto such an example. The configuration of the light collection unit 130and properties of the optical members that form the light collectionunit 130 may appropriately be designed in consideration of a positionalrelationship between the light guide unit 120 and the fluorescentsubstance wheel 140, characteristics of the light from the light sourceunit 110, which serves as the excitation light, and characteristics ofthe fluorescent light emitted from the fluorescent substance of thefluorescent substance wheel 140, for example.

There is a possibility that if a specific position on the fluorescentsubstance is continuously irradiated with the light from the lightsource unit 110, light emitting properties of the fluorescent substancemay be degraded due to heat caused by the irradiation with the light,for example. Since the relative position of the light collection spot143 on the fluorescent substance wheel 140 may be constantly changed byirradiating the fluorescent substance wheel 140 with the light whilerotating the fluorescent substance wheel 140, such degradation in theperformance of the fluorescent substance can be avoided.

The fluorescent light emitted from the fluorescent substance of thefluorescent substance wheel 140 is isotropically radiated from the lightcollection spot 143. The fluorescent light is collected by the lightcollection unit 130, is guided in the incident direction of theexcitation light (that is, the negative direction of the Z axis),becomes substantially parallel light, ad is incident on the spectroscopyunit 150 provided between the light guide unit 120 and the lightcollection unit 130. In FIG. 1, the fluorescent light emitted from thefluorescent substance of the fluorescent substance wheel 140 isrepresented by a wide arrow while the light from the light source unit110 is represented by a solid line arrow for convenience ofillustration.

As described above, the light collection unit 130 has a function ofcollecting the light, which has been guided by the light guide unit 120,at the light collection spot 143 and also has a function of collectingthe fluorescent light, which has been emitted from the fluorescentsubstance of the fluorescent substance wheel 140 in the light collectionunit 130. Therefore, such an optical design of the light collection unit130 in which the light collection unit 130 suitably realizes these twofunctions is employed.

The light collection unit 130 is preferably arranged at a position asclose to the fluorescent substance wheel 140 as possible. By arrangingthe light collection unit 130 at a position close to the fluorescentsubstance wheel 140, it is possible to more efficiently collect thefluorescent light emitted from the fluorescent substance of thefluorescent substance wheel 140 and to improve usage efficiency of thefluorescent light.

The spectroscopy unit 150 is provided on an optical path of light thatis directed from the light guide unit 120 toward the fluorescentsubstance wheel 140. The spectroscopy unit 150 is formed of a dichroicmirror that has a capability of transmitting light in the wavelengthband corresponding to the light from the light source unit 110 andreflecting light in the wavelength band corresponding to the fluorescentlight emitted from the fluorescent substance of the fluorescentsubstance wheel 140, for example. However, the first embodiment is notlimited to such an example, and the spectroscopy unit 150 can be formedof an arbitrary optical member that has a function of separating thelight from the light source unit 110 and the fluorescent light from thefluorescent substance wheel 140.

As shown in the drawing, the light source device 10 is configured suchthat the light guide unit 120, the spectroscopy unit 150, the lightcollection unit 130, and the fluorescent substance wheel 140 are alignedsubstantially in one array in the Z axis direction in this order. Thelight from the light source unit 110 is guided in the positive directionof the Z axis by the light guide unit 120, is then transmitted throughthe spectroscopy unit 150, and is collected at the light collection spot143 on the fluorescent substance of the fluorescent substance wheel 140by the light collection unit 130. The fluorescent light emitted from thefluorescent substance of the fluorescent substance wheel 140 is guidedin the negative direction of the Z axis by the light collection unit 130and is then reflected by the spectroscopy unit 150.

In the illustrated example, the dichroic mirror forming the spectroscopyunit 150 is arranged at an angle of about 45° with respect to adirection in which the fluorescent light is emitted from the fluorescentsubstance wheel 140 (that is, with respect to the Z axis direction), andthe fluorescent light is guided toward the Y axis direction by thedichroic mirror. The fluorescent light guided toward the Y axisdirection is extracted outward as light output from the light sourcedevice 10 via an output lens 151.

The configuration of the light source device according to the firstembodiment has been described above with reference to FIG. 1. Theconfiguration example illustrated in FIG. 1 simply schematically showsthe configuration of the light source device according to the firstembodiment. The light source device 10 may further include variousoptical members, which are not illustrated, in the configurationillustrated in FIG. 1. For example, a diffuser plate may be provided ata stage previous to the incidence of the light from the light sourceunit 110 on the fluorescent substance wheel 140. By providing thediffuser plate, laser light from the plurality of LDs of the lightsource unit 110 is appropriately diffused, and the light collection spot143 can be formed as a region with a predetermined size. Various otheroptical members that can be mounted on a typical light source device canfurther be mounted on the light source device 10.

Optical design of the various optical members, such as the concavemirror 121 and the convex mirror 122, that are mounted on the lightsource device 10 can be appropriately performed by using simulation suchas light beam tracking. For example, a desired position and a size ofthe light collection spot 143 can be set in accordance with desiredproperties of the fluorescent light and light emitting properties of thefluorescent substance of the fluorescent substance wheel 140, forexample. The optical design of the respective optical members may beperformed by creating a calculation model in which the various opticalmembers are arranged in the same manner as in the light source device 10and repeatedly executing simulation while changing shapes, arrangementpositions, optical properties, and the like of the respective opticalmembers so as to realize the desired position and size of the lightcollection spot 143.

Here, although the respective optical members of the light source device10 are designed so as to realize the desired position and size of thelight collection spot 143 as described above, the position and the sizeof the light collection spot 143 may deviate from designed values inpractice due to variations in manufacturing the respective opticalmembers and positional deviations during assembly, for example. If theposition and the size of the light collection spot 143 greatly deviatefrom the designed values, there is a possibility that light collectionefficiency of the fluorescent light in the light collection unit 130 maybe degraded and the quality (for example, parallelism and intensity) ofthe fluorescent light emitted via the light collection unit 130 may bedegraded. Therefore, an operation of adjusting the position and the sizeof the light collection spot 143 is performed during assembly of thelight source device 10 or when the light source device 10 is installedin an apparatus such as a projector, in some cases.

Here, the light from the light source unit 110 is reflected by theconcave mirror 121 and the convex mirror 122 in this order and is guidedtoward the light collection spot 143 on the fluorescent substance wheel140 in the light source device 10 as described above. At this time, theconcave mirror 121 and the convex mirror 122 can be arranged such thatthe optical axes thereof (the central axis of the paraboloidal surfaceforming the reflective surface of the concave mirror 121 and the centralaxis of the spherical surface forming the reflective surface of theconvex mirror) substantially coincide with each other. Furthermore, theoptical axis of the light collection unit 130 is also provided so as tosubstantially coincide with the optical axes of the concave mirror 121and the convex mirror 122. Since the optical axes of the lightcollection optical system that collects the light from the light sourceunit 110 at the light collection spot 143 are aligned as describedabove, the positions of the light collection spot 143 in the X axisdirection and the Y axis direction can be respectively adjusted bymoving the positions of the convex mirror 122 in the X axis directionand the Y axis direction in the light source device 10. Also, the sizeof the light collection spot 143 can be adjusted by moving the positionof the convex mirror 122 in the Z axis direction.

As described above, since the position in the X axis direction, theposition in the Y axis direction, and the size of the light collectionspot 143 can be respectively independently adjusted by moving the convexmirror 122 in parallel to the three axis directions in the light sourcedevice 10, the light collection spot 143 can be more easily and moreprecisely adjusted. The moving of the convex mirror 122 in parallel tothe three axis directions can be realized by the aforementionedadjustment mechanism, for example. In the first embodiment, thepositions of the convex mirror 122 in the three axis directions arefinely adjusted by the adjustment mechanism, and the position and thesize of the light collection spot 143 are adjusted during the assemblyof the light source device 10 or when the light source device 10 isinstalled in an apparatus such as a projector.

1-2. Comparison with Typical Light Source Device

According to the first embodiment, it is possible to more easily andmore precisely adjust the light collection spot 143 as described above.Here, comparison will be made between the light source device 10according to the first embodiment and a typical existing light sourcedevice in order to more clearly describe the effect of the firstembodiment. Here, comparison will be made with a configuration based onthe light source device described in Patent Literature 1 as an exampleof a typical existing light source device.

1-2-1. Comparison of Device Configurations

First, a configuration of a typical light source device will bedescribed, and comparison will be made with the configuration of thelight source device 10 according to the first embodiment.

The configuration of the typical light source device will be describedwith reference to FIG. 2. FIG. 2 is a diagram illustrating aconfiguration example of the typical light source device.

Referring to FIG. 2, a typical light source device 90 mainly includes alight source unit 910, a light guide unit 920, a light collection unit930, a fluorescent substance wheel 940, and a spectroscopy unit 950.Here, the aforementioned light source device described in PatentLiterature 1 uses a transmissive-type fluorescent substance wheel. Thelight source device 90 illustrated in FIG. 2 corresponds to aconfiguration obtained by applying a reflective-type fluorescentsubstance wheel 940 rather than the transmissive-type fluorescentsubstance wheel unlike the light source device described in PatentLiterature 1.

The light source unit 910 emits substantially parallel light in apredetermined wavelength band. The light source unit 910 includes atleast one LD that is a solid-state light source and at least onecollimator lens that substantially parallelizes the light emitted fromthe LD. Since the configuration and the function of the light sourceunit 910 can be the same as the configuration and the function of thelight source unit 110 according to the first embodiment, detaileddescription thereof will be omitted.

The light guide unit 920 guides the light from the light source unit 910toward the fluorescent substance wheel 940. The light guide unit 920includes a concave mirror 921, a planar mirror 922, and a collimatingoptical system 923. The light from the light source unit 910 isreflected by the concave mirror 921 and the planar mirror 922 in thisorder, becomes substantially parallel light by being transmitted throughthe collimating optical system 923, and is guided toward the fluorescentsubstance wheel 940.

The concave mirror 921 is arranged such that a reflective surfacethereof faces the light source unit 910. The concave mirror 921 reflectsthe light from the light source unit 910 toward the planar mirror 922.

The planar mirror 922 is arranged such that a reflective surface thereoffaces the concave mirror 921. The light from the light source unit 910,which has been reflected by the concave mirror 921 and has been incidenton the planar mirror 922, is guided in the positive direction of the Zaxis. In FIG. 2, the light from each of the plurality of LDs of thelight source unit 910 is represented by a single representative solidline in the same manner as in FIG. 1. The light after being reflected bythe planar mirror 922 is represented by a single representative solidline.

Here, the light reflected by the planar mirror 922 is not substantiallyparallel light and is collected at a predetermined point in the positivedirection of the Z axis. The light source device 90 includes thecollimating optical system 923 at the light collection position. Thecollimating optical system 923 is formed of a lens group for causinglight to become substantially parallel light, causing the lightreflected by the planar mirror 922 to become substantially parallellight, and guiding the substantially parallel light toward thefluorescent substance wheel 940.

The fluorescent substance wheel 940 includes a disk-shaped substrate941, a fluorescent substance (not illustrated) provided on the substrate941, and a motor 942 that is provided at the center of the substrate 941and drives the fluorescent substance wheel 940. Since configurations andfunctions of the fluorescent substance wheel 940, and the substrate 941,the fluorescent substance, the motor 942, and the like that form thefluorescent substance wheel 940 can be the same as the configurationsand the functions of the fluorescent substance wheel 140, the substrate141, the fluorescent substance, the motor 142, and the like according tothe first embodiment, detailed description thereof will be omitted.Since a configuration and a function of the light collection unit 930can also be the same as the configuration and the function of the lightcollection unit 130 according to the first embodiment, detaileddescription thereof will be omitted.

In the light source device 90, substantially parallel light obtained bythe collimating optical system 923 is collected by the light collectionunit 930 and is collected at a light collection spot 943 on thefluorescent substance of the fluorescent substance wheel 940. Thefluorescent light radiated from the light collection spot 943 is guidedin an incident direction of the light from the light source unit 910(that is, the negative direction of the Z axis) by the light collectionunit 930, becomes substantially parallel light, and is incident on thespectroscopy unit 950 provided between the light guide unit 920 and thelight collection unit 930.

The spectroscopy unit 950 is formed of a dichroic mirror, for example.The fluorescent light emitted from the fluorescent substance of thefluorescent substance wheel 940 is reflected by the dichroic mirror andis extracted outward as light output from the light source device 90 viaan output lens 951. Since a configuration and a function of thespectroscopy unit 950 can be the same as the configuration and thefunction of the spectroscopy unit 150 according to the first embodiment,detailed description thereof will be omitted.

The configuration of the typical light source device has been describedabove with reference to FIG. 2. Here, the aforementioned light sourcedevice described in Patent Literature 1 is configured such that atransmissive-type fluorescent substance wheel is arranged at the lightcollecting position of the light reflected by the planar mirror 922(that is, the position corresponding to the arrangement position of thecollimating optical system 923 in the drawing) and the light reflectedby the planar mirror 922 is collected on the fluorescent substance ofthe fluorescent substance wheel. Since the fluorescent light is emittedfrom a surface on the opposite side in the incident direction of theexcitation light in the case of the transmissive-type fluorescentsubstance wheel, the fluorescent light is emitted in the positivedirection of the Z axis if the transmissive-type fluorescent substancewheel is arranged as described above in the configuration illustrated inFIG. 2.

However, it is difficult to directly arrange the reflective-typefluorescent substance wheel 940 at the light collection position of thelight reflected by the planar mirror 922 if it is considered that thereflective-type fluorescent substance wheel 940 is applied to theaforementioned light source device described in Patent Literature 1.This is because it is necessary to arrange the light collection unit forcollecting the fluorescent light on the side of the surface, from whichthe fluorescent light is emitted, of the fluorescent substance wheel 940since the light emitted from the fluorescent substance of thefluorescent substance wheel 940 is isotropically radiated as describedabove. That is, it becomes necessary to arrange a lens or the like forcollecting the fluorescent light between the planar mirror 922 and thefluorescent substance wheel 940 if the reflective-type fluorescentsubstance wheel 940 is arranged at the light collection position of thelight reflected by the planar mirror 922 illustrated in FIG. 2. However,if the lens is provided, the light reflected by the planar mirror 922 isnot collected on the fluorescent substance of the fluorescent substancewheel 940.

If the reflective-type fluorescent substance wheel 940 is used asdescribed above, the light collection unit and other optical membershave to be configured such that the light collection unit provided at astage previous to the fluorescent substance wheel 940 (on the incidentside of the excitation light and the emitting side of the fluorescentlight) has both the functions of collecting the excitation light at thefluorescent substance of the fluorescent substance wheel and collectingthe fluorescent light radiated from the fluorescent substance.Therefore, if the reflective-type fluorescent substance wheel 940 isapplied to the aforementioned light source device described in PatentLiterature 1, the collimating optical system 923 is provided at thelight collection position of the light reflected by the planar mirror922, and the light collection unit 930 and the fluorescent substancewheel 940 are provided at a stage thereafter.

In contrast, the convex mirror 122 instead of the planar mirror 922 isprovided at the position at which the planar mirror 922 in the lightsource device 90 illustrated in FIG. 2 is provided, in the light sourcedevice 10 according to the first embodiment as illustrated in FIG. 1.Furthermore, since the concave mirror 121 and the convex mirror 122 arearranged such that the optical axes of the concave mirror 121 and theconvex mirror 122 substantially coincide with each other, the lightreflected by the convex mirror 122 is guided as substantially parallellight toward the fluorescent substance wheel 140. Therefore, it is notnecessary to provide an optical member corresponding to the collimatingoptical system 923 illustrated in FIG. 9. A larger number of opticalmembers correspondingly lead to an increase in the total amount of lossof light when the light passes through the optical members. Also, thelight source device increases in size, and there is also a concern thatthe manufacturing costs may also increase. It is possible to reduce thenumber of optical components in the light source device 10 according tothe first embodiment as compared with the typical light source device 90and to thereby realize a highly-efficient small-sized light sourcedevice at low cost.

1-2-2. Comparison of Methods for Adjusting Light Collection Spot

Here, the method of adjusting the light collection spot 143 in the lightsource device 10 according to the first embodiment and a method ofadjusting the light collection spot 943 in the typical light sourcedevice 90 as described above will be compared.

In the typical light source device 90, it is possible to adjust theposition and the size of the light collection spot 943 by changing anangle between the reflective surface of the planar mirror 922 and the Zaxis (an angle of the planar mirror 922 with respect to the Z axisdirection) due to the configuration thereof. Here, a problem that mayoccur in changing the angle of the planar mirror 922 will be consideredwith reference to FIGS. 3A and 3B. FIGS. 3A and 3B are explanatorydiagrams for explaining a change in an angle of a planar mirror 922 ofthe typical light source device 90.

If a specific mechanism for changing the angle of the planar mirror 922with respect to the Z axis direction is considered, where the positionof the rotation axis thereof is to be set is important. This is becausethe position of the planar mirror 922 in the Z axis direction alsochanges along with rotation of the planar mirror 922 when the planarmirror 922 is rotated with respect to the Z axis direction.

Ideally, it is desirable that the rotation axis of the planar mirror 922is provided at substantially the center in a longitudinal direction asillustrated in FIG. 3A. This is because in this case, the change in theposition of the planar mirror 922 in the Z axis direction can beminimized when the planar mirror 922 rotates about the rotation axis asthe center.

However, the mechanism in which the rotation axis is provided at theposition illustrated in FIG. 3A has a complicated configuration, whichis not practical. It is conceivable that the actual rotation axis may beprovided at an end in the longitudinal direction as illustrated in FIG.3B in many cases. However, if the rotation axis is provided at the endin the longitudinal direction, the position of the planar mirror 922 inthe Z axis direction greatly changes along with the rotation of theplanar mirror 922.

illustrates light intensity distribution when the planar mirror 922 isthe angle of the planar mirror 922 with respect to the Z axis directionwas changed. The result is shown in FIGS. 4A, 4B and 4C. FIGS. 4A, 4Band 4C are diagrams illustrating a change in the light collection spot943 when the angle of the planar mirror 922 with respect to the Z axisdirection is changed in the typical light source device 90.

FIGS. 4A, 4B and 4C illustrate light intensity distribution in apredetermined region in an X-Y plane where the light collection spot 943is present when the angle of the planar mirror 922 with respect to the Zaxis direction is changed. In the drawing, a region with a strongerwhite color represents a region with higher light intensity. That is,the white region represents the light collection spot 943.

FIG. 4A illustrates light intensity distribution when the planar mirror922 is arranged at the designed position. In FIG. 4A, the substantiallycircular light collection spot 943 is present at substantially thecenter in the region illustrated in the drawing.

In contrast, FIG. 4B illustrates a light intensity distribution when theplanar mirror 922 is rotated by 0.5° with respect to the Z axisdirection. However, only the angle of the planar mirror 922 is changedwhile the position in the Z axis direction is not changed in FIG. 4B soas to correspond to the situation illustrated in FIG. 3A. Referring toFIG. 4B, it can be understood that the position of the light collectionspot 943 has moved in parallel to the Y axis direction in accordancewith the change in the angle of the planar mirror 922 as compared withthe case illustrated in FIG. 4A. The size of the light collection spot943 does not substantially change. Ideally, it is possible to adjustonly the position of the light collection spot 943 when only the angleof the planar mirror 922 is changed without changing the positionthereof in the Z axis direction as described above.

However, the rotation axis of the planar mirror 922 is provided at theend in the longitudinal direction as described above with reference toFIG. 3B in practice in many cases. Therefore, the position of the planarmirror 922 in the Z axis direction can greatly change in conjunctionwith the rotation thereof.

FIG. 4C illustrates a light intensity distribution when a change in theposition in the Z axis direction has occurred at the same time byrotating the planar mirror 922 by 0.5° with respect to the Z axisdirection so as to correspond to the situation illustrated in FIG. 3B.Referring to FIG. 4C, it can be understood that the position of thelight collection spot 943 has moved and the size thereof has alsochanged in accordance with the change in the angle and the position ofthe planar mirror 922 as compared with the case illustrated in FIG. 4A.

The result illustrated in FIG. 4C illustrates that the size of the lightcollection spot 943 also changes when the angle of the planar mirror 922with respect to the Z axis direction is changed in order to adjust onlythe position of the light collection spot 943 in the typical lightsource device 90. As described above, it is difficult to respectivelyindependently adjust the position and the size of the light collectionspot 943 in the typical light source device 90, and it is difficult tostate that the light collection spot 943 can be easily adjusted.

In contrast, the positions of the light collection spot 143 in the Xaxis direction and the Y axis direction can be respectively adjusted bymoving the positions of the convex mirror 122 in the X axis directionand the Y axis direction in the light source device 10 according to thefirst embodiment as described above in (1-1. Configuration of lightsource device). Also, it is possible to adjust the size of the lightcollection spot 143 by moving the position of the convex mirror 122 inthe Z axis direction.

The present inventors produced an apparatus for experiments with thesame configuration as that of the light source device 10 illustrated inFIG. 1 and examined a change in the light collection spot 143 when theconvex mirror 122 was moved in the X axis direction, the Y axisdirection, and the Z axis direction. The result is shown in FIGS. 5A,5B, 5C, 6A, 6B, 6C and 6D. FIGS. 5A, 5B and 5C are diagrams illustratinga change in the light collection spot 143 when the convex mirror 122 ismoved in the X axis direction and the Y axis direction in the lightsource device 10 according to the first embodiment. FIGS. 6A, 6B, 6C and6D are diagrams illustrating a change in the light collection spot 143when the convex mirror 122 is moved in the Z axis direction in the lightsource device 10 according to the first embodiment.

FIGS. 5A, 5B and 5C illustrate a light intensity distribution in apredetermined region in an X-Y plane where the light collection spot 143is present when the positions of the convex mirror 122 in the X axisdirection and the Y axis direction are changed. FIGS. 6A, 6B, 6C and 6Dillustrate a light intensity distribution in the predetermined region inthe X-Y plane where the light collection spot 143 is present when theposition of the convex mirror 122 in the Z axis direction is changed. InFIGS. 5A, 5B, 5C, 6A, 6B, 6C and 6D, a region with a stronger whitecolor in the drawing represents a region with higher light intensity inthe same manner as in FIGS. 4A, 4B and 4C. That is, it is possible tostate that the white region represents the light collection spot 143.

FIG. 5A illustrates a light intensity distribution when the convexmirror 122 is arranged at the designed position. In FIG. 5A, thesubstantially circular light collection spot 143 is present atsubstantially the center in the illustrated region.

FIG. 5B illustrates a light intensity distribution when the position ofthe convex mirror 122 in the X axis direction is changed by −0.4 (mm).Referring to FIG. 5B, it can be understood that the position of thelight collection spot 143 has moved in the X axis direction inaccordance with the movement of the convex mirror 122 in the X axisdirection as compared with the case illustrated in FIG. 5A. At thistime, the size of the light collection spot 143 has substantially notchanged.

FIG. 5C illustrates a light intensity distribution when the position ofthe convex mirror 122 in the Y axis direction is moved by −0.4 (mm).Referring to FIG. 5C, it can be understood that the position of thelight collection spot 143 has moved in the Y axis direction inaccordance with the movement of the convex mirror 122 in the Y axisdirection as compared with the case illustrated in FIG. 5A. At thistime, the size of the light collection spot 143 has substantially notchanged in the same manner as in the case illustrated in FIG. 5B.

It can be recognized from the result illustrated in FIGS. 5A, 5B and 5Cthat the positions of the light collection spot 143 in the respectiveaxial directions in the X-Y plane can be independently adjusted bychanging the position of the convex mirror 122 in the X-Y plane in thelight source device 10 according to the first embodiment.

FIG. 6A illustrates an intensity distribution when the convex mirror 122is arranged at the designed position in the same manner as in FIG. 5A.In FIG. 6A, the substantially circular light collection spot 143 ispresent at substantially the center in the illustrated region.

FIGS. 6B, 6C and 6D illustrate a light intensity distribution when thearrangement position of the convex mirror 122 in the Z axis direction ischanged by 0.1 (mm), 0.2 (mm), and 0.3 (mm), respectively. Referring toFIGS. 6B, 6C and 6D, it can be understood that the size of the lightcollection spot 143 has gradually increased in accordance with themovement of the convex mirror 122 in the Z axis direction as comparedwith the case illustrated in FIG. 6A. At this time the position of thelight collection spot 143 has substantially not changed. The size of thelight collection spot 143 has changed more greatly in the verticaldirection than in the horizontal direction in the drawing because theLDs forming the light source unit 110 are aligned in the Y axisdirection as illustrated in FIG. 1 in the apparatus for experiments. Itis possible to isotropically change the size of the light collectionspot 143 by contriving a configuration of the LDs for this.

It can be recognized from the result illustrated in FIGS. 6A, 6B, 6C and6D that the size of the light collection spot 143 can be adjusted bychanging the position of the convex mirror 122 in the Z axis directionin the light source device 10 according to the first embodiment.

As illustrated in FIGS. 5A, 5B, 5C, 6A, 6B, 6C and 6D, the position inthe X axis direction, the position in the Y axis direction, and the sizeof the light collection spot 143 can be respectively independentlyadjusted by moving the convex mirror 122 in parallel to the three axisdirections in the light source device 10. Therefore, it is possible tomore easily and more precisely adjust the position and the size of thelight collection spot 143 as compared with the typical light sourcedevice 90 in which the position and the size of the light collectionspot 943 change in conjunction with each other.

Here, a mechanism of moving a member in parallel can be more simplyconfigured than a mechanism of rotating the member, in general. Also, amechanism of moving a member in parallel and then holding a constantposition thereof with high precision can be more easily realized than amechanism of rotating the member and then holding a constant positionthereof with high precision. Therefore, the light source device 10 doesnot significantly increase in size even if the adjustment mechanism ofmoving the convex mirror 122 in parallel to the three axis directions isprovided inside the light source device 10. Also, a constant positionand size of the light collection spot 143 can be maintained with highprecision by the position of the convex mirror 122 being held with highprecision. According to the first embodiment, it is possible to moreeasily and more precisely adjust the light collection spot 143 with asimpler configuration than that of the typical light source device 90.By more precisely adjusting the light collection spot 143, it ispossible to further improve the quality of the fluorescent light emittedfrom the fluorescent substance and to further improve the quality of thelight output from the light source device 10.

Here, it is also possible to drive the light source device 10 so as tofurther extend a lifetime of the fluorescent substance of thefluorescent substance wheel 140 by using the mechanism of adjusting theposition of the convex mirror 122 in one modification example of thefirst embodiment. For example, the adjustment mechanism may beconfigured to automatically operate in accordance with a program, andthe adjustment mechanism may dynamically change the position of theconvex mirror 122 in the X-Y plane while the light source device 10 isdriven. In this manner, the position of the light collection spot 143dynamically changes while the light source device 10 is driven.Therefore, it is possible to greatly change the relative position of thelight collection spot 143 on the fluorescent substance wheel 140 alongwith the rotation of the fluorescent substance wheel 140, thereby tofurther minimize degradation in the performance of the fluorescentsubstance, and to obtain a long lifetime of the fluorescent substancewheel 140.

Hereinafter, other embodiments of the present disclosure will bedescribed in (2. Second embodiment) to (6. Sixth embodiment). Theembodiments described below correspond to change of a part of theoptical members or addition of new optical members, which are made withrespect to the configuration of the light source device 10 according tothe first embodiment as described above. Therefore, detailed descriptionof matters overlapping with those in the first embodiment will beomitted, and matters different from those in the first embodiment willbe mainly described in the following description of the respectiveembodiments. Since main configurations in the following respectiveembodiments are the same as that in the first configuration, the sameeffects as the effects that can be achieved by the first embodiment asdescribed above can be obtained. Matters described in the aforementionedfirst embodiment and the respective embodiment described below may becombined with each other within a possible range.

2. Second Embodiment

Referring to FIG. 7, a configuration of a light source device accordingto a second embodiment of the present disclosure will be described. FIG.7 is a diagram illustrating a configuration example of the light sourcedevice according to the second embodiment.

Referring to FIG. 7, a light source device 20 according to the secondembodiment mainly includes light source units 110, a light guide unit220, a light collection unit 130, a fluorescent substance wheel 140, anda spectroscopy unit 150. The light source device 20 according to thesecond embodiment corresponds to a configuration obtained by changingthe configuration of the light guide unit 120 with respect to the lightsource device 10 according to the aforementioned first embodiment. Sinceconfigurations and functions of the other optical members are the sameas those in the first embodiment, detailed description thereof will beomitted.

The light guide unit 220 is configured such that pairs of the lightsource units 110 and the concave mirrors 121 are symmetrically providedwith respect to the convex mirror 122 interposed therebetween. Lightemitted from the respective light source units 110 is respectivelyreflected by the concave mirrors 121 that are provided so as tocorrespond to the respective light source units 110 and is collected atthe convex mirror 122. The light emitted from the respective lightsource units 110 is further reflected by the convex mirror 122, iscollected by the light collection unit 130, and is collected at thelight collection spot 143 on the fluorescent substance of thefluorescent substance wheel 140.

As described above, a plurality of combinations of the light sourceunits 110 and the concave mirrors 121 are provided for one convex mirror122 in the light source device 20 according to the second embodiment. Inthis manner, it is possible to increase the intensity of excitationlight at the light collection spot 143 and to increase the intensity offluorescent light emitted from the fluorescent substance wheel 140 aswell.

Here, if it is attempted to increase the numbers of light source units910 and concave mirrors 921 in the typical light source device 90illustrated in FIG. 2, for example, it is necessary to additionallyprovide planar mirrors 922 so as to correspond to the light source units910 and the concave mirrors 921. In contrast, it is possible to reflectthe light from the plurality of light source units 110 and the concavemirrors 121 by one convex mirror 122 in the second embodiment and tothereby keep the device a relatively small size without any need toprovide additional convex mirrors 122.

Although the pairs of the light source units 110 and the concave mirrors121 are symmetrically provided in the Y axis direction with respect tothe convex mirror 122 interposed therebetween in the illustratedexample, the second embodiment is not limited to such an example. Thenumber in an arrangement and the arrangement position of thecombinations of the light source units 110 and the concave mirrors 121may be arbitrarily selected. For example, four pairs of the light sourceunits 110 and the concave mirrors 121 may be symmetrically provided inthe X axis direction and the Y axis direction with respect to the convexmirror 122 interposed therebetween. Alternatively, an arbitrary numberof combinations of the light source units 110 and the concave mirrors121 may be provided at arbitrary positions in the circumference of theconvex mirror 122.

3. Third Embodiment

A configuration of a light source device according to a third embodimentof the present disclosure will be described with reference to FIG. 8.FIG. 8 is a diagram illustrating a configuration example of a lightsource device according to the third embodiment.

Referring to FIG. 8, a light source device 30 according to the thirdembodiment mainly includes light source units 110, a light guide unit320, a light collection unit 130, a fluorescent substance wheel 140, anda spectroscopy unit 150. The light source device 30 according to thethird embodiment corresponds to a configuration obtained by changing theconfiguration of the light guide unit 120 with respect to the lightsource device 10 according to the aforementioned first embodiment. Sinceconfigurations and functions of the other optical members are the sameas those in the first embodiment, detailed description thereof will beomitted.

The light guide unit 320 is configured such that pairs of the lightsource units 110 and the concave mirrors 121 are symmetrically providedwith respect to a pair of convex mirrors 323 a and 323 b interposedtherebetween. The pair of convex mirrors 323 a and 323 b have a shapeobtained by dividing the convex mirror 122 with the substantiallysemi-spherical shape illustrated in FIG. 1 into halves. In the followingdescription, the convex mirrors 323 a and 323 b will also be referred toas divided convex mirrors 323 a and 323 b for convenience in order todistinguish the convex mirrors 323 a and 323 b from the convex mirror122.

Light output from a first light source unit 110 is reflected by a firstconcave mirror 121 provided so as to correspond to the first lightsource unit 110 and is collected by the divided convex mirror 323 a. Thedivided convex mirror 323 a further reflects the light emitted from thefirst light source unit 110 and guides the light toward the fluorescentsubstance wheel 140. In contrast, light emitted from a second lightsource unit 110 that is different from the first light source unit 110is reflected by a second concave mirror 121 provided so as to correspondto the second light source unit 110 and is collected at the dividedconvex mirror 323 b. The divided convex mirror 323 b further reflectsthe light emitted from the second light source unit 110 and guides thelight toward the fluorescent substance wheel 140.

Both the light emitted from the first light source unit 110, which hasbeen guided by the divided convex mirror 323 a, and the light emittedfrom the second light source unit 110, which has been guided by thedivided convex mirror 323 b are collected by the light collection unit130 and are collected at the light collection spot 143 on thefluorescent substance of the fluorescent substance wheel 140.

As described above, the light guide unit 320 is configured such that thecombinations of the light source units 110 and the concave mirrors 121are respectively provided for the plurality of divided convex mirrors323 a and 323 b in the light source device 30. By providing theplurality of light source units 110 and the concave mirrors 121, it ispossible to increase the intensity of excitation light at the lightcollection spot 143 and to increase the intensity of fluorescent lightemitted from the fluorescent substance wheel 140 as well in the samemanner as in the aforementioned second embodiment.

Here, adjustment mechanisms for adjusting the positions of the pluralityof divided convex mirrors 323 a and 323 b in the three axis directionsmay be respectively provided for the divided convex mirrors 323 a and323 b in the third embodiment. In this manner, it is possible to adjustthe position and the size of the light collection spot 143 for each ofthe divided convex mirrors 323 a and 323 b.

A formation example of the light collection spot 143 in the light sourcedevice 30 according to the third embodiment will be described withreference to FIG. 9. FIG. 9 is a diagram illustrating a formationexample of the light collection spot 143 in the light source device 30according to the third embodiment. FIG. 9 illustrates a light intensitydistribution in a predetermined region in the X-Y plane where the lightcollection spot 143 is present in the same manner as in FIGS. 4A, 4B,4C, 5A, 5B, 5C, 6A, 6B, 6C and 6D. In the drawing, a region with astronger white color represents a region with higher light intensity,and it is possible to state that the white region represents the lightcollection spot 143.

As illustrated in the drawing, the positions of the light collectionspot 143 for each of the divided convex mirrors 323 a and 323 b areintentionally deviated from each other, for example, in the thirdembodiment. That is, a plurality of light collection spots 143 can beformed at different positions so as to correspond to each of theplurality of divided convex mirrors 323 a and 323 b. In this manner, itis possible to appropriately adjust the intensity such that theintensity of the excitation light, with which the fluorescent substanceis irradiated, does not become unnecessarily higher.

Here, it is known that at the fluorescent substance, the intensity ofthe incident excitation light and the intensity of the radiatedfluorescent light are not necessarily proportional to each other and theluminance of the fluorescent light becomes saturated as the intensity ofthe excitation light becomes higher. Therefore, it is not possible tofurther improve the luminance of the radiated fluorescent light even ifthe intensity of the excitation light that is incident on thefluorescent substance further increases in a region where the luminanceof the fluorescent light is saturated, which leads to a large loss interms of efficiency in conversion into the fluorescent light.

Thus, the positions of the divided convex mirrors 323 a and 323 b in thethree axis directions are respectively adjusted such that the lightcollection spots 143 deviate from each other for the divided convexmirrors 323 a and 323 b as illustrated in FIG. 9 in the thirdembodiment. That is, the plurality of light collection spots 143 areprovided at different positions. By providing the plurality of lightcollection spots 143 as described above and appropriately controllingthe light intensity at the respective light collection spots 143, thereis a possibility of it being possible to improve a conversion efficiencyof the fluorescent substance as a whole and to obtain fluorescent lightwith high luminance at the fluorescent substance as a whole as comparedwith the case where a single light collection spot 143 is irradiatedwith light with higher intensity. Also, since the light collection spots143 are dispersed, it is possible to reduce damage to the fluorescentsubstance due to the excitation light and to maximize the lifetime ofthe fluorescent substance.

Although two combinations of the light source units 110, the concavemirrors 121, and the divided convex mirrors are provided in the Y axisdirection in the illustrated example, the third embodiment is notlimited to such an example. The number in an arrangement and thearrangement position of the combinations of the light source units 110,the concave mirrors 121, and the divided convex mirrors may bearbitrarily selected. For example, a total of four sets of the lightsource units 110, the concave mirrors 121, and the divided convexmirrors may be provided such that two sets are provided in each of the Xaxis direction and the Y axis direction. In this case, each dividedconvex mirror has a shape obtained by dividing a substantiallysemi-spherical shape into four parts.

4. Fourth Embodiment

A configuration of a light source device according to a fourthembodiment of the present disclosure will be described with reference toFIG. 10. FIG. 10 is a diagram illustrating a configuration example ofthe light source device according to the fourth embodiment.

Referring to FIG. 10, a light source device 40 according to the fourthembodiment mainly includes a light source unit 110, a light guide unit120, light collection units 130 and 460, and a fluorescent substancewheel 440. The light source device 40 according to the fourth embodimentcorresponds to a configuration obtained by applying a transmissive-typefluorescent substance wheel 440 instead of the reflective-typefluorescent substance wheel 140 in the light source device 10 accordingto the aforementioned first embodiment. Correspondingly, thespectroscopy unit 150 is omitted from the light source device 10, andthe light collection unit 460 is added thereto in the light sourcedevice 40. Since configurations and functions of the other opticalmembers are the same as those in the first embodiment, detaileddescription thereof will be omitted.

As illustrated in the drawing, light from the light source unit 110,which has been guided by the light guide unit 120, is collected at thefluorescent substance on the substrate 141 of the fluorescent substancewheel 440 by the light collection unit 130. Since the fluorescentsubstance wheel 440 is a transmissive-type fluorescent substance wheel,fluorescent light is radiated in a direction opposite to an incidentdirection of excitation light. In the illustrated example, light (thatis, excitation light) from the light source unit 110 is incident on thefluorescent substance wheel 440 in the negative direction of the Z axis,and the fluorescent light is radiated in the positive direction of the Zaxis. Since a configuration and a function of the fluorescent substancewheel 440 are the same as the configuration and the function of thefluorescent substance wheel 140 according to the first embodiment otherthan that the fluorescent substance wheel 440 is a transmissive-typefluorescent substance wheel, detailed description thereof will beomitted.

The light collection unit 460 that collects the fluorescent light andguides the light as substantially parallel light toward optical membersin a later stage is provided on the fluorescent light radiation side ofthe fluorescent substance wheel 440. A configuration of the lightcollection unit 460 may be the same as that of the light collection unit130.

The fluorescent light collected by the light collection unit 460 isextracted outward as light output from the light source device 90 viathe output lens 151. Since the fluorescent light is isotropicallyradiated from the fluorescent substance of the fluorescent substancewheel 440, it is possible to more efficiently extract the fluorescentlight to the outside by the light collection unit 460 being provided onthe radiation surface thereof. In order to further improve the lightcollection efficiency of the fluorescent light, the light collectionunit 460 can be arranged at a position as close to the fluorescentsubstance wheel 440 as possible.

Here, since the reflective-type fluorescent substance wheel 140 is usedin the first embodiment, the incident direction of the excitation lightand the radiation direction of the fluorescent light are the samedirection, and the light collection unit 130 has both the function ofcollecting the excitation light at the fluorescent substance wheel 140and the function of collecting the fluorescent light radiated from thefluorescent substance wheel 140. In contrast, since thetransmissive-type fluorescent substance wheel 440 is used in the fourthembodiment, the light collection units 130 and 460 are provided on theincident side of the excitation light and the radiation side of thefluorescent light, respectively.

Although the case where the transmissive-type fluorescent substancewheel 440 was applied to the light source device 10 according to thefirst embodiment was described in FIG. 10 as a configuration example ofthe light source device 40 according to the fourth embodiment, thefourth embodiment is not limited to such an example. For example, thetransmissive-type fluorescent substance wheel 440 may be applied to thelight source devices 20 and 30 according to the aforementioned secondand third embodiments.

Another configuration example of the light source device according tothe fourth embodiment will be described as a modification example of thefourth embodiment with reference to FIG. 11. FIG. 11 is a diagramillustrating another configuration example of the light source deviceaccording to the fourth embodiment.

Referring to FIG. 11, a light source device 45 according to amodification example of the fourth embodiment mainly includes lightsource units 110, a light guide unit 320, light collection units 130 and460, and a fluorescent substance wheel 440. The light source device 45according to the modification example corresponds to an application ofthe transmissive-type fluorescent substance wheel 440 to the lightsource device 30 according to the aforementioned third embodiment.

As described above in (3. Third embodiment), the light guide unit 320 isconfigured such that the plurality of combinations of the light sourceunits 110, the concave mirrors 121, and the divided convex mirrors areprovided. In the light source device 45, light from the respective lightsource units 110 is respectively guided toward the fluorescent substancewheel 440 by the corresponding divided convex mirrors 323 a and 323 band is collected on the fluorescent substance by the light collectionunit 130. At this time, the positions of the light collection spots 143may be deviated for each of the divided convex mirrors 323 a and 323 bas illustrated in FIG. 9 by respectively adjusting the arrangementpositions of the divided convex mirrors 323 a and 323 b in the threeaxis directions.

According to the modification example, dispersion of the lightcollection spots 143 as described above in (3. Third embodiment) isrealized also for the transmissive-type fluorescent substance wheel 440,and it is possible to realize an increase in luminance of thefluorescent light and a long lifetime of the fluorescent substance wheel440.

5. Fifth Embodiment

A configuration of a light source device according to a fifth embodimentof the present disclosure will be described with reference to FIG. 12.FIG. 12 is a diagram illustrating a configuration example of the lightsource device according to the fifth embodiment.

Referring to FIG. 12, a light source device 50 according to the fifthembodiment mainly includes light source units 110, a light guide unit320, a light collection unit 130, a fluorescent substance wheel 140, anda spectroscopy unit 350. The light source device 50 according to thefifth embodiment corresponds to a configuration obtained by changing anarrangement of the respective optical members and correspondinglychanging the function of the spectroscopy unit 150 in the light sourcedevice 30 according to the aforementioned third embodiment. Sinceconfigurations and functions of the other optical members aresubstantially the same as those in the third embodiment, detaileddescription thereof will be omitted.

The spectroscopy unit 350 in the fifth embodiment can be formed of adichroic mirror in the same manner as in the first to third embodiments.However, the dichroic mirror in the fifth embodiment has a transmissionproperty and a reflection property opposite to those in the first tothird embodiments. That is, the dichroic mirror according to the fifthembodiment has a capability of reflecting light in the wavelength bandcorresponding to the light from the light source unit 110 andtransmitting light in the wavelength band corresponding to thefluorescent light radiated from the fluorescent substance of thefluorescent substance wheel 140.

As illustrated in the drawing, the light source device 50 is providedwith the light collection unit 130 and the fluorescent substance wheel140 that have optical axes in a direction substantially perpendicular toan advancing direction of the light guided by the light guide unit 320.Light guided in the positive direction of the Z axis by the light guideunit 320 is reflected by the spectroscopy unit 350 provided in theadvancing direction thereof, and an optical path thereof is changed byabout 90°. In the illustrated example, the optical path of the light ischanged to the positive direction of the Y axis by the spectroscopy unit350. Then, the light is collected at the light collection spot 143 onthe fluorescent substance of the fluorescent substance wheel 140 by thelight collection unit 130.

The fluorescent light radiated from the fluorescent substance byirradiation with the excitation light is collected by the lightcollection unit 130, becomes substantially parallel light, and is guidedtoward the spectroscopy unit 350 (that is, in the negative direction ofthe Y axis). Since the spectroscopy unit 350 has the capability oftransmitting the light in the wavelength band corresponding to thefluorescent light in the fifth embodiment, the fluorescent lightradiated from the fluorescent substance wheel 140 is transmitted throughthe spectroscopy unit 350 and directly advances in the negativedirection of the Y axis. Then, the fluorescent light is extracted towardthe outside as light output from the light source device 50 via theoutput lens 151.

According to the fifth embodiment, it is possible to change thearrangement positions of the light collection unit 130 and thefluorescent substance wheel 140 with respect to the light source devices10, 20, and 30 according to the first to third embodiments by using thedichroic mirror with properties different from those in the first tothird embodiments as the spectroscopy unit 350 as described above. Whichof the configuration as in the light source devices 10, 20, and 30according to the first to third embodiments and the configuration as inthe light source device 50 according to the fifth embodiment is to beapplied in terms of the arrangement positions of the light collectionunit 130 and the fluorescent substance wheel 140 may be appropriatelyselected in consideration of easiness in operations when the lightsource devices 10, 20, 30, and 50 are assembled, the sizes of casebodies of the light source devices 10, 20, 30, and 50, and the like.

6. Sixth Embodiment

The light source devices according to the aforementioned respectiveembodiments are designed to directly output the fluorescent light, whichis radiated from the fluorescent substance, as the output light thereof.As described above in (1-1. Configuration of light source device), aYAG-based fluorescent substance is used as the fluorescent substance.

Here, properties of the fluorescent light emitted from the YAG-basedfluorescent substance will be described with reference to FIG. 13. FIG.13 is a graph illustrating a spectrum of the fluorescent light in theYAG-based fluorescent substrate.

In FIG. 13, a wavelength of the fluorescent light emitted from theYAG-based fluorescent substance is represented on the horizontal axis,an intensity of normalized fluorescent light is represented on thevertical axis, and a relationship therebetween is plotted. Referring toFIG. 13, it can be understood that components from the green band to thered band are included while substantially no components in a blue bandare included in the fluorescent light emitted from the YAG-basedfluorescent substance. Therefore, it is necessary to supplement light inthe blue band in order to output white light from the light sourcedevice using the YAG-based fluorescent substance in the light source.

The sixth embodiment is designed to realize the light source device thatoutputs white light, by adding a light source unit that outputs light ina blue band to the configurations of the light source devices accordingto the aforementioned respective embodiments.

A configuration of the light source device according to the sixthembodiment of the present disclosure will be described with reference toFIG. 14. FIG. 14 is a diagram illustrating a configuration example ofthe light source device according to the sixth embodiment.

Referring to FIG. 14, a light source device 60 according to the sixthembodiment mainly includes light source units 110, a light guide unit320, a light collection unit 130, a fluorescent substance wheel 140, aspectroscopy unit 150, and an additional light source unit 670. Thelight source device 60 according to the sixth embodiment corresponds toa configuration obtained by adding the additional light source unit 670to the light source device 30 according to the aforementioned thirdembodiment. Since configurations and functions of the other opticalmembers are substantially the same as those in the third embodiment,detailed description thereof will be omitted.

The additional light source unit 670 emits light in a wavelength banddifferent from that of the fluorescent light radiated from thefluorescent substance of the fluorescent substance wheel 140. Forexample, if the YAG-based fluorescent substance is used as thefluorescent substance of the fluorescent substance wheel 140, theadditional light source unit 670 can be configured as a light sourcethat emits light in the blue band. However, the sixth embodiment is notlimited to such an example, and the additional light source unit 670 maybe appropriately configured so as to emit light with such a wavelengththat white light is generated when overlapped with the fluorescent lightfrom the fluorescent substance, in accordance with properties of thefluorescent substance of the fluorescent substance wheel 140.

As illustrated in the drawing, the additional light source unit 670 canbe arranged such that additional light from the additional light sourceunit 670 is overlapped with the fluorescent light as output light in thelight source device 60. In the illustrated example, the additional lightsource unit 670 is arranged on the side opposite to the output lens 151with the spectroscopy unit 150 interposed therebetween.

The additional light source unit 670 includes a light source unit 671and a lens group 672. The light source unit 671 may be the same as thelight source unit 110 that emits the excitation light for thefluorescent substance of the fluorescent substance wheel 140, and mayinclude at least one LD that emits laser light in the blue band and atleast one collimator lens that substantially parallelizes the lightemitted from the LD.

Light from the light source unit 671 passes through the lens group 672and is incident on the spectroscopy unit 150. Since the light sourceunit that outputs the light in the blue band in the same manner as thelight source unit 110 is used as the light source unit 671, the lightfrom the light source unit 671 is also transmitted through the dichroicmirror forming the spectroscopy unit 150. Therefore, the laser lightemitted from the light source unit 671 passes through the lens group 672and the spectroscopy unit 150 and is combined with the fluorescent lightradiated from the fluorescent substance wheel 140 and reflected by thespectroscopy unit 150. In this manner, white light is obtained as thelight output from the light source device 60 by combining the light fromthe light source unit 671 and the fluorescent light from the fluorescentsubstance wheel 140.

Although the lens group 672 includes a plurality of plano-convex lensesin the illustrated example, the configuration of the lens group 672 isnot limited to such an example. The lens group 672 may be appropriatelyconfigured such that the light from the light source unit 671 and thefluorescent light are appropriately combined and the combined light hasdesired properties (for example, intensity and parallelism) as whitelight.

7. Application Examples

One application example of the light source device according to each ofthe aforementioned embodiments will be described. The light sourcedevice according to each of the embodiments can be suitably used as alight source of a projector, for example. Hereinafter, someconfiguration examples in which the light source device according toeach of the aforementioned embodiments is applied to a light source of aprojector will be described.

7-1. First Configuration Example

A first configuration example in which a light source device accordingto each of the aforementioned embodiments is applied will be describedwith reference to FIG. 15. FIG. 15 is a diagram illustrating aconfiguration of a projector according to the first configurationexample.

Referring to FIG. 15, a projector 1 according to the first configurationexample includes a light source device 60 and an image projection device1000. Here, since the configuration and the function of the light sourcedevice 60 have already been described above in (6. Sixth embodiment),detailed description thereof will be omitted herein.

The image projection device 1000 generates an image by using lightoutput from the light source device 60 and projects the image. The imageprojection device 1000 includes optical members such as a first fly-eyelens 1003, a second fly-eye lens 1005, a polarization conversion element1007, a condenser lens 1009, a cross dichroic mirror 1011, a reflectivemirrors 1015 and 1019, relay lenses 1017 and 1021, a dichroic mirror1023, wire grid-type polarization splitter elements 1025R, 1025G, and1025B, reflective-type liquid crystal panels 1027R, 1027G, and 1027B,and a cross prism 1029 that are mounted on the inside of the case body1001. A projection unit 1031 is provided in an emitting direction oflight combined by the cross prism 1029. The light source device 60 maybe assembled inside the case body 1001 along with the other opticalmembers.

Substantially parallel white light output from the light source device60 is incident on the inside of the case body 1001 of the imageprojection device 1000, then sequentially adds the first fly-eye lens1003, the second fly-eye lens 1005, the polarization conversion element1007, and the condenser lens 1009, and reaches the cross dichroic mirror1011.

The first fly-eye lens 1003 and the second fly-eye lens 1005 have afunction of aligning the incident light, with which the polarizationconversion element 1007 is irradiated, from the light source device 60into a uniform luminance distribution as a whole. The substantiallyparallel light that is incident from the light source device 60 isdivided into a plurality of light fluxes by microlenses of the firstfly-eye lens 1003, and images are respectively formed on correspondingmicrolenses of the second fly-eye lens 1005. Each of the microlenses ofthe second fly-eye lens 1005 functions as a secondary light source andirradiates the polarization conversion element 1007 with a plurality ofparallel light beams with a uniformized luminance as incident light.

The polarization conversion element 1007 has a function of uniformizingpolarization states of the incident light that is incident via the firstfly-eye lens 1003 and the second fly-eye lens 1005. The light in thepolarization state uniformized by the polarization conversion element1007 is incident on the cross dichroic mirror 1011 via the condenserlens 1009. In FIG. 15, arrows representing advancing directions of bluelight 1013B, green light 1013G, and red light 1013R, which arecomponents included in the incident light from the light source device60, are represented with arrows of mutually different line types in asimulation manner on an optical path after the condenser lens 1009.

The cross dichroic mirror 1011 is formed of a combination of twodichroic mirrors that have mutually different reflection properties andtransmission properties. In the first configuration example, the crossdichroic mirror 1011 is configured to split the blue light 1013B, thegreen light 1013G, and the red light 1013R from each other.

The blue light 1013B split by the cross dichroic mirror 1011 isreflected by the reflective mirror 1015, passes through the relay lens1017, and is incident on the wire grid-type polarization splitterelement 1025B and the reflective-type liquid crystal panel 1027B.

The wire grid-type polarization splitter element 1025B is formed byproviding a wire grid at an end surface (an end surface corresponding toan oblique side of a right-angled isosceles triangle), which functionsas an incident surface and a reflective surface, of a triangular prismhaving a bottom surface with a substantially right-angled isoscelestriangle shape. The wire grid-type polarization splitter element 1025Bis arranged such that the end surface at which the wire grid is providedforms an angle of about 45° with respect to an incident direction of theblue light 1013B. In addition, the reflective-type liquid crystal panel1027B is arranged on an extended line in the incident direction of theblue light 1013B with the wire grid-type polarization splitter element1025B interposed therebetween.

The wire grid-type polarization splitter element 1025B has a capabilityof reflecting S polarized light and transmitting P polarized light atthe end surface at which the wire grid is provided. Therefore, thepolarization of the blue light 1013B that has been incident on the wiregrid-type polarization splitter element 1025B is split, and only a Ppolarization component, for example, is incident on the reflective-typeliquid crystal panel 1027B.

A video signal is applied to the reflective-type liquid crystal panel1027B, and alignment of liquid crystal molecules in the panel arecontrolled by an applied electric field based on the video signal. Thepolarization state of the incident light is changed by the alignment ofthe liquid crystal molecules, and the incident light is reflected on thesame side as the incident direction. That is, the P polarized light thathas been incident on the reflective-type liquid crystal panel 1027Bbecomes S polarized light and is reflected in the direction in which theblue light 1013B has been incident. The light reflected by thereflective-type liquid crystal panel 1027B is blue light that forms anoptical image in accordance with the video image.

The light reflected by the reflective-type liquid crystal panel 1027B isincident again on the end surface at which the wire grid of the wiregrid-type polarization splitter element 1025B is provided. Since thelight reflected by the reflective-type liquid crystal panel 1027B is Spolarized, the light is reflected by the end surface and is incident onthe cross prism 1029 provided in the reflection direction.

In contrast, the green light 1013G and the red light 1013R split fromthe blue light 1013B by the cross dichroic mirror 1011 are guided alongan optical path different from that of the blue light 1013B, arereflected by the reflective mirror 1019, pass through the relay lens1021, and are incident on the dichroic mirror 1023. The dichroic mirror1023 has a capability of reflecting the green light 1013G andtransmitting the red light 1013R, and the green light 1013G and the redlight 1013R are split from each other by the dichroic mirror 1023.

The green light 1013G split by the dichroic mirror 1023 is incident onthe wire grid-type polarization splitter element 1025G and thereflective-type liquid crystal panel 1027G. The red light 1013R split bythe dichroic mirror 1023 is incident on the wire grid-type polarizationsplitter element 1025R and the reflective-type liquid crystal panel1027R.

Since configurations and functions of the wire grid-type polarizationsplitter elements 1025G and 1025R are the same as the configuration andthe function of the wire grid-type polarization splitter element 1025Band configurations and functions of the reflective-type liquid crystalpanels 1027G and 1027R are the same as the configuration and thefunction of the reflective-type liquid crystal panel 1027B, detaileddescription will be omitted herein. The S polarization component of thegreen light 1013G reflecting the video signal on the reflective-typeliquid crystal panel 1027G is made to be incident on the cross prism1029 by the wire grid-type polarization splitter element 1025G and thereflective-type liquid crystal panel 1027G, and the S polarizationcomponent of the red light 1013R reflecting the video signal on thereflective-type liquid crystal panel 1027R is incident on the crossprism 1029 with the wire grid-type polarization splitter element 1025Rand the reflective-type liquid crystal panel 1027R.

The cross prism 1029 overlaps and combines light of the respectivecolors that has been incident from the three directions and emits thelight toward the projection unit 1031. The projection unit 1031 isprovided with a plurality of lenses, which are not illustrated in thedrawing, and projects the light combined by the cross prism 1029 onto anexternal screen, for example, of the projector 1. In this manner, animage based on the video signal applied to the reflective-type liquidcrystal panels 1027R, 1027G, and 1027B is displayed in color.

The configuration of the projector 1 according to the firstconfiguration example has been described above. As described above, thelight source device 60 according to the sixth embodiment is used as thelight source of the projector 1 in the first configuration example.Here, if the position and the size of the light collection spot 143 onthe fluorescent substance of the fluorescent substance wheel 140 greatlydeviates from the designed values in the light source device 60, forexample, there is a possibility that the quality (for example, intensityand parallelism) of the white light output from the light source device60 may be degraded and thus the quality of the light projected by theprojector 1 may also degraded. If the quality of the light projected bythe projector 1 is degraded, there is a concern that image quality ofthe image projected by the projector 1 may deteriorate.

Here, it is possible to adjust the position and the size of the lightcollection spot 143 on the fluorescent substance of the fluorescentsubstance wheel 140 by a relatively simple method of adjusting thepositions of the divided convex mirrors 323 a and 323 b in the threeaxis directions in the light source device 60. Therefore, it is possibleto more easily perform the adjustment so as to improve the quality ofthe light projected from the projector 1 by performing such adjustmentof the light collection spot 143 when the light source device 60 isassembled in the projector 1, for example. It is possible to moreprecisely adjust the position and the size of the light collection spot143 in the light source device 60, thereby to improve the quality of theprojected light, and to obtain a projected image with higher quality.

7-2. Second Configuration Example

A second configuration example in which the light source deviceaccording to each of the aforementioned embodiments is applied will bedescribed with reference to FIG. 16. FIG. 16 is a diagram illustrating aconfiguration of a projector according to the second configurationexample.

The configuration example described below corresponds to a configurationobtained by changing a part of the optical components in theconfiguration of the projector 1 according to the aforementioned firstconfiguration example or adding a new optical member thereto. Therefore,detailed descriptions of matters overlapping with those in the firstconfiguration example will be omitted, and matters different from thosein the first configuration example will be mainly described in thefollowing description of the respective configuration examples. Sincemain configurations in the following respective configuration examplesare the same as that of the first configuration example, the same effectas that achieved by the aforementioned first configuration example canbe achieved. The matters described in the aforementioned firstconfiguration example and the respective configuration examplesdescribed below may be combined in a possible range.

Referring to FIG. 16, a projector 2 according to the secondconfiguration example includes a light source device 30, an additionallight source unit 670, and an image projection device 2000. Here, sincethe configuration and the function of the light source device 30 havealready been described above in (3. Third embodiment), detaileddescription thereof will be omitted herein. Since the configuration andthe function of the additional light source unit 670 have already beendescribed above in (6. Sixth embodiment), detailed description thereofwill be omitted herein. Also, any of the aforementioned light sourcedevices 10, 20, 40, and 50 may be used instead of the light sourcedevice 30.

As illustrated in the drawing, the projector 2 includes the light sourcedevice 30 and the additional light source unit 670 respectively providedas light sources. The light source device 30 functions as a light sourcethat outputs light from the green band to the red band, and theadditional light source unit 670 functions as a light source thatoutputs light in the blue band. Correspondingly, the image projectiondevice 2000 includes a route through which the light from the green bandto the red band from the light source device 30 is incident and a routethrough which the light in the blue band from the additional lightsource unit 670 is incident provided as separate routes.

The configuration of the image projection device 2000 is the same asthat of the image projection device 1000 according to the firstconfiguration example other than the plurality of incident routescorresponding to the plurality of light sources are provided. Therefore,points different from the image projection device 1000 will be mainlydescribed in the following description of the image projection device2000.

The image projection device 2000 includes optical members such as afirst optical system 2003, a second optical system 2005, relay lenses1017 and 1021, a dichroic mirror 1023, wire grid-type polarizationsplitter elements 1025R, 1025G, and 1025B, reflective-type liquidcrystal panels 1027R, 1027G, and 1027B, and a cross prism 1029 mountedon the inside of the case body 2001. In addition, a projection unit 1031is provided in an emitting direction of light combined by the crossprism 1029. The light source device 30 and the additional light sourceunit 670 may be assembled inside the case body 2001 along with the otheroptical members.

Since configurations and functions of the relay lenses 1017 and 1021,the dichroic mirror 1023, the wire grid-type polarization splitterelements 1025R, 1025G, and 1025B, the reflective-type liquid crystalpanels 1027R, 1027G, and 1027B, the cross prism 1029, and the projectionunit 1031 are the same as the configurations and the functions of thesemembers described above in (7-1. First configuration example), detaileddescription thereof will be omitted.

The image projection device 2000 includes a first optical system 2003provided on an incident route corresponding to the light source device30 and a second optical system 2005 provided on the incident routecorresponding to the additional light source unit 670.

The first optical system 2003 includes a first fly-eye lens 1003, asecond fly-eye lens 1005, a polarization conversion element 1007, and acondenser lens 1009.

Substantially parallel light from the green band to the red band outputfrom the light source device 30 is incident on the inside of the casebody 2001 of the image projection device 2000, sequentially adds theseoptical members of the first optical system 2003, and reaches the relaylens 1021. Here, since configurations and functions of the first fly-eyelens 1003, the second fly-eye lens 1005, the polarization conversionelement 1007, and the condenser lens 1009 are the same as theconfigurations and the functions of these members described above in(7-1. First configuration example), detailed description thereof will beomitted.

Light output from the light source device 30, which has been incident onthe relay lens 1021, is incident on the dichroic mirror 1023 and issplit into green light 1013G and red light 1013R. The green light 1013Gis incident on the wire grid-type polarization splitter element 1025Gand the reflective-type liquid crystal panel 1027G. The red light 1013Ris incident on the wire grid-type polarization splitter element 1025Rand the reflective-type liquid crystal panel 1027R. Since behaviors ofthe green light 1013G and the red light 1013R on the optical paths afterthe relay lens 1021 are the same as those described above in (7-1. Firstconfiguration example), detailed description thereof will be omitted.

The second optical system 2005 includes a first fly-eye lens 1003, asecond fly-eye lens 1005, and a condenser lens 1009. Substantiallyparallel blue laser light output from the additional light source unit670 is incident on the inside of the case body 2001 of the imageprojection device 2000, sequentially adds these optical members of thesecond optical system 2005, and reaches the relay lens 1017. Here, thepolarization conversion element 1007 that is provided in the firstoptical system 2003 can be suitably omitted from the second opticalsystem 2005. This is because the light output from the additional lightsource unit 670 is laser light and polarization states thereof havealready been uniformized.

Light (that is, the blue light 1013B) output from the additional lightsource unit 670, which has been incident on the relay lens 1017, isincident on the wire grid-type polarization splitter element 1025B andthe reflective-type liquid crystal panel 1027B. Since a behavior of theblue light 1013B on the optical path after the relay lens 1017 is thesame as that described above in (7-1. First configuration example),detailed description thereof will be omitted.

The red light 1013 R, the green light 1013G, and the blue light 1013Breflecting the video signal are incident on the cross prism 1029, andthe cross prism 1029 overlaps and combines the light of the respectivecolors that has been incident from the three directions, and emits thelight toward the projection unit 1031. The projection unit 1031 projectsthe light combined by the cross prism 1029 on an external screen, forexample, of the projector 2, and an image based on the video signal isdisplayed in color.

The configuration of the projector 2 according to the secondconfiguration example has been described above. As described above, thelight source device 30 and the additional light source unit 670 are usedas the light sources of the projector 2 in the second configurationexample. The additional light source unit 670 is for supplementing thewavelength band component that is not included in the light output fromthe light source device 30.

By preparing the additional light source unit 670 as a separate lightsource without it being assembled in the light source device 30 andcausing the light from the additional light source unit 670 and thelight source device 30 to be incident on the image projection device2000 through the respectively separate routes, it is possible to reducea burden on the optical members on the incident route of the imageprojection device 2000 and to extend lifetime of these optical members.Therefore, a more reliable projector 2 is realized.

In addition, the light source device 30 has a simpler configuration ascompared with the light source device 60 including the additional lightsource unit 670 assembled therein. By forming the light source device 30with a smaller number of optical members, it is possible to improvereliability of the light source device 30 itself.

Here, it is possible to realize a projector that is compatible with awider wavelength band by further adding a light source unit capable ofemitting light in a wavelength band different from that of theadditional light source unit 670 to the light source device 30 in thesecond configuration example.

FIG. 17 illustrates a configuration of a projector when such a lightsource unit capable of emitting light in a wavelength band differentfrom that of the additional light source unit 670 is further added tothe light source device 30 as a modification example of the secondconfiguration example. FIG. 17 is a diagram illustrating a configurationof the projector according to the modification example of the secondconfiguration example.

Referring to FIG. 17, a projector 3 according to the modificationexample corresponds to a configuration obtained by adding an additionallight source unit 2007 to the light source device 30 in the projector 2illustrated in FIG. 16. The additional light source unit 2007 is a lightsource unit that emits light in a wavelength band different from that ofthe additional light source unit 670. The additional light source unit2007 is arranged at a position similar to the arrangement position ofthe additional light source unit 670 described above in (6. Sixthembodiment) in the light source device 30.

For example, the additional light source unit 2007 includes a lightsource 2009 that emits infrared light and a lens group 2011. Theinfrared light emitted from the light source 2009 passes through thelens group 2011, becomes substantially parallel light, is combined withfluorescent light radiated from the fluorescent substance wheel 140, andis incident on the image projection device 2000. With such aconfiguration, the light emitted from the projector 3 becomes light in awider wavelength including an infrared band. The projector 3 can beutilized for simulation when a device that can use both visible lightand infrared light, such as a night vision device, is developed.

7-3. Third Configuration Example

A third configuration example in which the light source device accordingto each of the aforementioned embodiments is applied to a projector willbe described with reference to FIG. 18. FIG. 18 is a diagramillustrating a configuration of the projector according to the thirdconfiguration example.

Referring to FIG. 18, a projector 4 according to the third configurationexample includes a light source device 30, an additional light sourceunit 670, and an image projection device 1000. Here, since theconfiguration and the function of the light source device 30 havealready been described above in (3. Third embodiment), detaileddescription thereof will be omitted herein. Also, since theconfiguration and the function of the additional light source unit 670have already been described above in (6. Sixth embodiment), detaileddescription thereof will be omitted herein. In addition, any of theaforementioned light source devices 10, 20, 40, and 50 may be usedinstead of the light source device 30.

As illustrated in the drawing, the projector 4 includes the light sourcedevice 30 and the additional light source unit 670 respectively providedas light sources. However, unlike the projector 2 according to thesecond configuration example, the light from the light source device 30and the light from the additional light source unit 670 are combined ata stage previous to the incidence of the light on the image projectiondevice 1000, and the combined light is incident on the image projectiondevice 1000 through the same route in the projector 4.

Specifically, a dichroic mirror 4001 is provided at the stage previousto the incidence of the light output from the light source device 30 onthe image projection device 1000, and a reflective mirror 4003 thatguides the light from the additional light source unit 670 toward thedichroic mirror 4001 is provided in the emitting direction of the lightfrom the additional light source unit 670 as illustrated in the drawing,for example. The dichroic mirror 4001 has a property of transmitting thelight from the green band to the red band from the light source device30 and reflecting the blue laser light from the additional light sourceunit 670, and the combined light thereof is incident on the imageprojection device 1000. The configuration of combining the light fromthe light source device 30 and the light from the additional lightsource unit 670 is not limited to the illustrated example, and may beappropriately set.

As described above, the third configuration example corresponds to thecombination of the first configuration example and the secondconfiguration example. Since a behavior of the combined light afterbeing incident on the image projection device 1000 is the same asdescribed above in (7-1. First configuration example), detaileddescription thereof will be omitted.

The configuration of the projector 4 according to the thirdconfiguration example has been described above. As described above, thelight source device 30 and the additional light source unit 670 are usedas the light sources of the projector 4 in the fourth configurationexample. In addition, the light from the light source device 30 and thelight from the additional light source unit 670 are combined at thestage previous to the incidence on the image projection device 1000, andthe combined light is incident on the image projection device 1000through the same route.

Here, when an incident route to the image projection device 2000 isformed so as to correspond to each light source as in the projector 2according to the aforementioned second configuration example, there is apossibility that the case body 2001 of the image projection device 2000may increase in size and the projector 2 itself may increase in size dueto the plurality of incident routes provided although it is possible toreduce the burden on the optical members in each incident route.According to the third configuration example, there is a possibilitythat the projector 4 can be further downsized while securing thereliability of the light sources by using the highly reliable lightsource device 30 with a simpler configuration and using the imageprojection device 1000 with the case body 1001 that can be furtherdownsized.

7-4. Fourth Configuration Example

A fourth configuration example in which the light source deviceaccording to each of the aforementioned embodiments is applied to aprojector will be described with reference to FIG. 19. FIG. 19 is adiagram illustrating a configuration of a projector according to thefourth configuration example. While the first to third configurationexamples use reflective-type liquid crystal panels, the fourthconfiguration example corresponds to a configuration using atransmissive-type liquid crystal panel.

Referring to FIG. 19, a projector 5 according to the fourthconfiguration example includes a light source section 70 and an imageprojection device 5000.

The light source section 70 outputs white light substantially inparallel to the image projection device 5000. As the light sourcesection 70, the light source device 60 according to the aforementionedsixth embodiment or a combination of any of the light source devices 10,20, 30, 40, and 50 according to the first to fifth embodiments as usedin the third configuration example and the additional light source unit670 is used.

The image projection device 5000 generates an image by using lightoutput from the light source section 70 and projects the image. Theimage projection device 5000 includes optical members such as a firstfly-eye lens 1003, a second fly-eye lens 1005, a polarization conversionelement 1007, a condenser lens 1009, dichroic mirrors 5003 and 5005,reflective mirrors 5007, 5009, and 5011, relay lenses 5013 and 5015,field lenses 5017R, 5017G, and 5017B, liquid crystal light valves 5019R,5019G, and 5019B, and a cross prism 1029 that are mounted on the insideof the case body 5001. Also, a projection unit 1031 is provided in anemitting direction of light combined by the cross prism 1029. The lightsource section 70 may be assembled inside the case body 5001 along withthe other optical members.

Substantially parallel white light output from the light source section70 is incident on the inside of the case body 5001 of the imageprojection device 5000, sequentially adds the first fly-eye lens 1003,the second fly-eye lens 1005, the polarization conversion element 1007,and the condenser lens 1009, and reaches the dichroic mirror 5003. Sinceconfigurations and functions of the first fly-eye lens 1003, the secondfly-eye lens 1005, the polarization conversion element 1007, and thecondenser lens 1009 are the same as the configurations and the functionsof these members described above in (7-1. First configuration example),detailed description thereof will be omitted.

The dichroic mirrors 5003 and 5005 have a characteristic of selectivelyreflecting light in a predetermined wavelength band and transmittinglight in the other wavelength bands. For example, the dichroic mirror5003 is configured so as to reflect the red light 1013 R and transmitthe blue light 1013B and the green light 1013G.

The red light 1013R which has been selectively reflected and split bythe dichroic mirror 5003 is reflected by the reflective mirror 5007, isparallelized by passing through the field lens 5017R, and is thenincident on the liquid crystal light valve 5019R for modulating the redlight.

The liquid crystal light valve 5019R includes a transmissive-type liquidcrystal panel and a polarization panel, for example. A video signal isapplied to the transmissive-type liquid crystal panel of the liquidcrystal light valve 5019R, a polarization state of the red light 1013Rpassing through the liquid crystal light valve 5019R is modulated foreach pixel, and the light is incident on the cross prism 1029 as redlight forming an optical image in accordance with the video signal.

In contrast, the blue light 1013B and the green light 1013G transmittedthrough the dichroic mirror 5003 are incident on the dichroic mirror5005 at a later stage. The dichroic mirror 5005 is configured to reflectthe green light 1013G and transmit the blue light 1013B.

The green light 1013G that has been selectively reflected and split bythe dichroic mirror 5005 is parallelized by passing through the fieldlens 5017G and is then incident on the liquid crystal light valve 5019Gfor modulating the green light. Also, the blue light 1013B transmittedthrough the dichroic mirror 5005 sequentially passes through the relaylens 5013, the reflective mirror 5009, the relay lens 5015, and thereflective mirror 5011, is parallelized by passing through the fieldlens 5017B, and is then incident on the liquid crystal light valve 5019Bfor modulating the blue light.

Since configurations and functions of the liquid crystal light valve5019G and the liquid crystal light valve 5019B are the same as those ofthe aforementioned liquid crystal light valve 5019R, detaileddescription thereof will be omitted. The polarization state of the greenlight 1013G passing through the liquid crystal light valve 5019G ismodulated for each pixel, and the light is incident on the cross prism1029 as green light forming an optical image in accordance with thevideo signal. Similarly, the polarization state of the blue light 1013Bpassing through the liquid crystal light valve 5019B is modulated foreach pixel, and the light is incident on the cross prism 1029 as greenlight forming an optical image in accordance with the video signal.

The cross prism 1029 overlaps and combines the light of the respectivecolors that has been incident from the three directions and emits thelight toward the projection unit 1031. The projection unit 1031irradiates an external screen or the like of the projector 5 with thelight combined by the cross prism 1029. In this manner, an image basedon the video signal applied to the transmissive-type liquid crystalpanels of the liquid crystal light valves 5019R, 5019G, and 5019B isdisplayed in color. Since configurations and functions of the crossprism 1029 and the projection unit 1031 are the same as theconfigurations and the functions of these members described above in(7-1. First configuration example), detailed description thereof will beomitted.

The configuration of the projector 5 according to the fourthconfiguration example has been described above. As described above, thelight source device according to each of the aforementioned embodimentscan be suitably applied to the projector 4 using the transmissive-typeliquid crystal panel.

7-5. Summary of Application Examples

The cases where these light source devices have been applied to theprojectors have been described above as application examples of thelight source devices according to the aforementioned respectiveembodiments. As described above, it is possible to more easily adjustthe light collection spot on the fluorescent substance in the lightsource device according to the respective embodiments of the presentdisclosure, and thereby to more easily improve the quality of lightprojected by the projector when the quality deteriorates due topositional deviation of the light collection spot, for example, byapplying these light source devices to the projector. Also, it ispossible to more precisely adjust the light collection spot in the lightsource devices according to the respective embodiments, thereby toimprove the quality of light projected by the projector, and to obtain aprojected image with higher quality.

Specific configurations of the image projection devices 1000, 2000, and5000 and the projection unit 1031 in the respective configurationexamples described above are not limited to the illustratedconfigurations. Various existing configurations that can be used for atypical projector may be applied as the image projection devices 1000,2000, and 5000 and the projection unit 1031.

The application examples of the light source devices according to therespective embodiments of the present disclosure are not limited to theprojector. The light source devices may be applied to other apparatuses.For example, the light source devices may be applied to illuminationapparatuses. By applying the light source devices to an illuminationapparatus, it becomes possible to more easily adjust the quality ofirradiation light of the illumination apparatus and to maintain a highquality for the irradiation light.

8. Supplementary Notes

The preferred embodiment(s) of the present disclosure has/have beendescribed above with reference to the accompanying drawings, whilst thepresent disclosure is not limited to the above examples. A personskilled in the art may find various alterations and modifications withinthe scope of the appended claims, and it should be understood that theywill naturally come under the technical scope of the present disclosure.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art from the description of this specification.

Additionally, the present technology may also be configured as below.

(1)

A light source device including:

at least one light source unit that emits substantially parallel lightin a predetermined wavelength band; and

a light guide unit that guides the light from the light source unittoward a light collection spot,

wherein the light from the light source unit is sequentially reflectedby a concave mirror and a convex mirror and is guided toward the lightcollection spot in the light guide unit.

(2)

The light source device according to (1),

wherein the concave mirror and the convex mirror are arranged such thata central axis of a reflective surface shape of the concave mirrorsubstantially coincides with a central axis of a reflective surfaceshape of the convex mirror.

(3)

The light source device according to (1) or (2), further including:

an adjustment mechanism that independently adjusts respective positionsof the convex mirror in three axis directions.

(4)

The light source device according to any one of (1) to (3),

wherein the light collection spot is provided on a fluorescent substancethat emits fluorescent light in response to the light from the lightsource unit.

(5)

The light source device according to (4),

wherein a fluorescent substance wheel with a substrate on which thefluorescent substance is provided is a reflective-type fluorescentsubstance wheel that radiates fluorescent light in a same direction asan incident direction of the light from the light source unit.

(6)

The light source device according to (4),

wherein a fluorescent substance wheel with a substrate on which thefluorescent substance is provided is a transmissive-type fluorescentsubstance wheel that radiates fluorescent light in a direction oppositeto an incident direction of the light from the light source unit.

(7)

The light source device according to any one of (1) to (6),

wherein a reflective surface shape of at least any of the concave mirrorand the convex mirror is an aspherical shape.

(8)

The light source device according to any one of (1) to (7),

wherein a plurality of combinations, each of which includes the lightsource unit and the concave mirror, are provided for the one convexmirror.

(9)

The light source device according to (8),

wherein the combinations, each of which includes the light source unitand the concave mirror, are provided so as to be symmetric with respectto the convex mirror interposed therebetween.

(10)

The light source device according to (8) or (9),

wherein divided convex mirrors with a shape obtained by dividing theconvex mirror are provided so as to correspond to the plurality ofrespective combinations, each of which includes the light source unitand the concave mirror,

light that is emitted from a first light source unit and is reflected bya first concave mirror is reflected by a first divided convex mirror andis guided toward the light collection spot, and

light that is emitted from a second light source unit and is reflectedby a second concave mirror is reflected by a second divided convexmirror and is guided toward the light collection spot.

(11)

The light source device according to (10),

wherein a plurality of the light collection spots are formed atdifferent positions so as to correspond to the plurality of respectivedivided convex mirrors.

(12)

The light source device according to any one of (1) to (11),

wherein a position of the light collection spot in a plane perpendicularto light reflected by the convex mirror is dynamically changed byadjustment of a position of the convex mirror in the plane duringdriving of the light source device.

(13)

The light source device according to any one of (1) to (12),

wherein the light collection spot is provided on a fluorescent substancethat emits fluorescent light in response to the light from the lightsource unit,

the light source device further includes a second light source unit thatemits light in a wavelength band different from that of the fluorescentlight, and

the light source device outputs light obtained by combining thefluorescent light and the light emitted from the second light sourceunit.

(14)

A projector including:

a light source device that includes

-   -   at least one light source unit that emits substantially parallel        light in a predetermined wavelength band and    -   a light guide unit that guides the light from the light source        unit toward a light collection spot; and

an image projection device that generates an image by using the lightoutput from the light source device and projects the image,

wherein the light from the light source unit is sequentially reflectedby a concave mirror and a convex mirror and is guided toward the lightcollection spot in the light guide unit of the light source device.

REFERENCE SIGNS LIST

-   1, 2, 3, 4, 5 projector-   10, 20, 30, 40, 50, 60 light source device-   70 light source section-   110 light source unit-   120, 220, 320 light guide unit-   121 concave mirror-   122 convex mirror-   130 light collection unit-   140, 440 fluorescent substance wheel-   143 light collection spot-   150, 350 spectroscopy unit-   323 a, 323 b divided convex mirror-   1000, 2000, 5000 image projection device

1. A projector, comprising: a light source device; and an imageprojection device, wherein the light source device includes at least onelight source section configured to emit substantially parallel light ina wavelength band, a light guide section configured to guide thesubstantially parallel light emitted from the at least one light sourcesection toward a light collection spot, and an adjustment mechanismconfigured to independently adjust respective positions of the at leastone convex mirror in three axis directions.
 2. The projector accordingto claim 1, wherein the light collection spot is on a fluorescentsubstance, wherein the fluorescent substance emits fluorescent light inresponse to the substantially parallel light emitted from the at leastone light source section.
 3. The projector according to claim 2, furthercomprising: a reflective-type fluorescent substance wheel with asubstrate, wherein the fluorescent substance is on the substrate, andwherein the reflective-type fluorescent substance wheel radiatesfluorescent light in a same direction as an incident direction of thesubstantially parallel light emitted from the at least one light sourcesection.
 4. The projector according to claim 2, further comprising: atransmissive-type fluorescent substance wheel with a substrate, whereinthe fluorescent substance is on the substrate, and wherein thetransmissive-type fluorescent substance wheel radiates fluorescent lightin a direction opposite to an incident direction of the substantiallyparallel light emitted from the at least one light source section. 5.The projector according to claim 1, wherein the light guide sectioncomprises at least one concave mirror and at least one convex mirror. 6.The projector according to claim 5, wherein a reflective surface shapeof at least one of the at least one concave mirror or the at least oneconvex mirror is an aspherical shape.
 7. The projector according toclaim 5, wherein a plurality of combinations, each of which includes theat least one light source section and the at least one concave mirror,are provided for the at least one convex mirror.
 8. The projectoraccording to claim 7, wherein the plurality of combinations, each ofwhich includes the at least one light source section and the at leastone concave mirror, are provided so as to be symmetric with respect tothe at least one convex mirror interposed therebetween.
 9. The projectoraccording to claim 5, wherein the substantially parallel light emittedfrom the at least one light source section is sequentially reflected bythe at least one concave mirror and the at least one convex mirror, andis guided toward the light collection spot in the light guide section.10. The projector according to claim 5, wherein the at least one concavemirror and the at least one convex mirror are arranged such that acentral axis of a reflective surface shape of the at least one concavemirror substantially coincides with a central axis of a reflectivesurface shape of the at least one convex mirror;
 11. The projectoraccording to claim 5, wherein divided convex mirrors with a shapeobtained by dividing a convex mirror of the at least one convex mirrorare provided so as to correspond to a plurality of respectivecombinations, each of which includes the at least one light sourcesection and the at least one concave mirror, wherein the divided convexmirrors comprise a first divided convex mirror and a second dividedconvex mirror, wherein light that is emitted from a first light sourcesection of the at least one light source section and is reflected by afirst concave mirror, is reflected by the first divided convex mirrorand is guided toward the light collection spot, and wherein light thatis emitted from a second light source section of the at least one lightsource section and is reflected by a second concave mirror, is reflectedby the second divided convex mirror and is guided toward the lightcollection spot.
 12. The projector according to claim 11, wherein aplurality of the light collection spots are formed at differentpositions so as to correspond to the respective divided convex mirrors.13. The projector according to claim 1, wherein a position of the lightcollection spot in a plane perpendicular to light reflected by the atleast one convex mirror is dynamically changed by adjustment of aposition of the light guide section in the plane during a drivingoperation of the light source device.
 14. The projector according toclaim 1, wherein the light collection spot is on a fluorescent substancethat emits fluorescent light in response to the substantially parallellight emitted from the at least one light source section.
 15. Theprojector according to claim 14, wherein the light source device furthercomprises a light source section configured to emit light in awavelength band different from that of the fluorescent light, andwherein the light source device is configured to output light obtainedby combining the fluorescent light and the light emitted from the lightsource section.